Color is a vital dimension of our limited communication abilities. Stripping away colors that a person who is color blind can’t see does no more for that person than turning off the entire picture does for a person who is completely without sight. It’s the presence of an alternate set of cues for that person that is important.
Generating artificial obsolescence through fashion is a time-honoured and effective way to move products from clothing to cars. A new fashion should not and need not, however, detract from user-performance. User test after making aesthetic changes, benchmarking the new design against the old. Ensure that learnability, satisfaction, and productivity have improved or at least stayed the same. If not, newly added aesthetics that are causing a problem need to be rethought.
Most people have color displays nowadays. However, approximately 10% of human males, along with fewer than 1% of females, have some form of color blindness.
Search Google for simulation tools. For example, for websites, you might try http://enably.com/chrometric/. For images, http://www.colblindor.com/coblis-color-blindness-simulator/.
Color Theory in Web UI Design - from UXpin.com